I studied Jane Austen's Northanger Abbey as one of my A level English texts. This is a send up of the gothic novel. The first task our teacher set us at the start of the course was to write a chapter from a supposedly long lost Gothic novel, based on the information about these novels in Northanger Abbey.
It was great fun and a really good start to our course. Perhaps the OP and his friends could start by doing something like that. It would teach them a lot about how the effects of such a book are constructed and give him/her a guide to how the style is created.